Bottom Line:
We investigated 42 patients who had unusual pruritic dermatitis associated with a specific clinical sign (comet sign) in 23 houses in southeastern France from May through September 2007.Pyemotes ventricosus, a parasite of the furniture beetle Anobium punctatum, was the cause of this condition.

ABSTRACTWe investigated 42 patients who had unusual pruritic dermatitis associated with a specific clinical sign (comet sign) in 23 houses in southeastern France from May through September 2007. Pyemotes ventricosus, a parasite of the furniture beetle Anobium punctatum, was the cause of this condition.

Figure 1: A–F) Photographs of 6 persons with skin lesions of Pyemotes ventricosus dermatitis. Note the central microvesicles, ulcerations or crusts, and some lesions with the comet sign. D) Lymphangitis-like dermatitis. E, F) Lesions resulting from natural infection of 2 of the investigators.

Mentions:
In 2006, we described an outbreak of unusual dermatitis in southeastern France (1). Patients affected had highly erythematous pruritic macules typical of arthropod bites, sometimes associated with a linear erythematous macular tract that we called the comet sign (Figure 1). The cause of this outbreak remained unknown. In May 2007, during an entomologic ecoenvironmental investigation conducted inside the homes of some of these patients, we found wooden furniture, which harbored live furniture beetles (Anobium punctatum) (Figure 2, panel A), and small amounts of wood dust on the floor. Because A. punctatum does not bite humans or cause contact dermatitis (2), it was not considered as the direct causative agent. However, stereomicroscope examination of the wood dust identified the mite Pyemotes ventricosus (Figure 2, panel B). Because Pyemotes spp. can cause dermatitis (3), they were considered as the hypothetical agent causing the eruption. We then conducted an observational and entomologic study of the new cases.

Figure 1: A–F) Photographs of 6 persons with skin lesions of Pyemotes ventricosus dermatitis. Note the central microvesicles, ulcerations or crusts, and some lesions with the comet sign. D) Lymphangitis-like dermatitis. E, F) Lesions resulting from natural infection of 2 of the investigators.

Mentions:
In 2006, we described an outbreak of unusual dermatitis in southeastern France (1). Patients affected had highly erythematous pruritic macules typical of arthropod bites, sometimes associated with a linear erythematous macular tract that we called the comet sign (Figure 1). The cause of this outbreak remained unknown. In May 2007, during an entomologic ecoenvironmental investigation conducted inside the homes of some of these patients, we found wooden furniture, which harbored live furniture beetles (Anobium punctatum) (Figure 2, panel A), and small amounts of wood dust on the floor. Because A. punctatum does not bite humans or cause contact dermatitis (2), it was not considered as the direct causative agent. However, stereomicroscope examination of the wood dust identified the mite Pyemotes ventricosus (Figure 2, panel B). Because Pyemotes spp. can cause dermatitis (3), they were considered as the hypothetical agent causing the eruption. We then conducted an observational and entomologic study of the new cases.

Bottom Line:
We investigated 42 patients who had unusual pruritic dermatitis associated with a specific clinical sign (comet sign) in 23 houses in southeastern France from May through September 2007.Pyemotes ventricosus, a parasite of the furniture beetle Anobium punctatum, was the cause of this condition.

ABSTRACTWe investigated 42 patients who had unusual pruritic dermatitis associated with a specific clinical sign (comet sign) in 23 houses in southeastern France from May through September 2007. Pyemotes ventricosus, a parasite of the furniture beetle Anobium punctatum, was the cause of this condition.